This invention relates to collated screwstrips comprising a holding strip, preferably of plastic, retaining a plurality of screws in a row and, more particularly, to such screwstrips of relatively short discrete Length.
Screwstrips are known wherein the screws are connected together by a retaining belt preferably of plastic material and adapted to be fed into an autofeed screw fastening tool and successively driven from the belt as the screwstrip is advanced through the tool. Known screwstrips of this type include those referred to and disclosed in the present applicant""s U.S. Pat. No. 5,758,768, issued Jun. 2, 1998 and U.S. Pat. No. 5,927,163, issued Jul. 27, 1999, the disclosures of which are incorporated herein by reference. Such screwstrips are adapted to be driven in autofeed screwdrivers, such as taught by the applicant""s U.S. Pat. No. 5,568,753, issued Oct. 29, 1996, U.S. Pat. No. 5,934,162, issued Aug. 10, 1999 and U.S. Pat. No. 5,870,933, issued Feb. 16, 1999, the disclosures of which are incorporated herein by reference.
Such screwstrips in one form are disposed in a helical coil containing, for example, up to 500 screws to be placed in a canister to retain the screwstrip and from which canister, a lead end of the screwstrip is placed into the autofeed screwdriver and advanced thereto to drive successive screws.
To avoid a user carrying the weight of the coil and canister, the present inventor has pioneered the use of such screwstrips of shorter discrete length, for example, 12 inches (30 cm), as taught by the aforementioned U.S. Pat. No. 5,758,768. Screwstrips of discrete length have two distal ends.
The present inventor has appreciated a disadvantage which arises is that users have difficulty in appreciating that, with many known screwstrips, proper loading into the autofeed screwdriver requires the correct one of the two distal ends to be inserted. Loading the incorrect distal end of the screwstrip into the autofeed screwdriver results in inoperation, jamming and/or mechanical failure of the autofeed screwdriving tool.
The present inventor has appreciated that short length screwstrips have two ends which a user may consider for feeding as a lead end into an autofeed screwdriver, however, that with many screwstrips, only one end can correctly be fed. The present inventor has appreciated that no easily discernable distinction arises between the two ends of the screwstrip.
The present inventor has also appreciated that difficulties can arise in loading the correct end of the screwstrip into the autofeed screwdrivers by reason of the distal lead end of the screwdriver engaging various surfaces in the autofeed screwdriver.
To at least partially overcome these disadvantages of previously known devices, the present invention provides a screwstrip with a front end of the holding strip having a forwardmost portion of reduced size compared to the remainder of the holding strip.
An object of the present invention is to provide a screwstrip with a holding strip having a front end with a shape which renders it visually apparent to a user that such end is the end to be fed into the autofeed screwdriving tool.
Another object is to provide a front end to the holding strip which facilitates passage of the end into an autofeed screwdriver.
Another object is to provide a screwstrip of finite length with two distal ends, one being a front end and the other being a rear end, the rear end having a configuration which renders it visually apparent to a user that the rear end is not the end to be inserted into an autofeed screwdriver.
Another object is to provide a screwstrip with a rear distal end which is configured to resist or prevent insertion of the rear distal end into an autofeed screwdriver.
Another object is to provide a method of manufacture of a screwstrip of discrete length by extruding a plastic holding strip onto the screws and cutting the strips such that a front edge has a first profile and the rear edge has a complimentary second profile.
Accordingly, in one aspect, the present intention provides a collated screwstrip comprising a holding strip and a plurality of fasteners, each fastener disposed about an axis and having a head at an upper end, a tip extending from the other end and a shank extending from below the head to the tip about the axis,
the holding strip holding the fasteners in a rose in spaced side-by-side relation with the axis of the fasteners in the common plane,
the holding strip comprising an elongate beam member which extends axially relative the fasteners and longitudinally between the fasteners,
the holding strip extending longitudinally from a front end to a rear end,
the holding strip having a width measured parallel the axis of the fasteners in a common plane;
a guide section of the holding strip at the front end extending longitudinally between the front end and a first fastener held by the holding strip rearward from the front end;
the width of the holding strip over a forwardmost portion of the guide section tapering to reduce towards the front end.
In another aspect, the present invention provides a method of forming screwstrips, wherein each screwstrip is of a fixed discrete length and having an array of screws of a predetermined number equally spaced therealong, the method comprising forming a screwstrip of a length to have a plurality of such arrays of screws along its length, each array spaced from an adjacent array by a length of the holding strip which does not carry screws, cutting the holding strip between the arrays along a cut line of a profile to provide on one side of the cut line a forward end of one screwstrip which tapers in width forwardly to a forward end and on the other side of the cut line a rear end of the another holding strap which is bifurcated over its width having a notch formed therein opening rearwardly from the cut line.
Further aspects and advantages of the present invention will appear from the following description taken together with the accompanying drawings, in which:
FIG. 1 is a pictorial view of a screwstrip in accordance with the first emnbodiment of the present invention;
FIG. 2 is a pictorial view of a short length of the screwstrip of FIG. 1 between section line 2-2xe2x80x2 and 22-22xe2x80x2 and showing; the other side of the screwstrip not shown in FIG. 1;
FIG. 3 is a schematic side view of the screwstrip of FIG. 1;
FIG. 4 is a schematic side view of portions of a screwstrip of the type shown in FIG. 1 showing a rear segment of one screwstrip as joined to a forward segment of the other screwstrip which are in the location of a cut to be made to separate the two strips;
FIG. 5 is a schematic pictorial view showing a second embodiment of a screwstrip similar to that shown in FIG. 1 passing through a nose portion of an autofeed screwdriver;
FIG. 6 is a cross-sectional view along section line 6-6xe2x80x2 in FIG. 5, prior to the screw being driven and showing a driver shaft;
FIG. 7 is a cross-sectional view similar to that of FIG. 6, however, showing a screw as the head of the screw is driven by the driver shaft past the holding strip;
FIG. 8 is a cross-sectional view similar to that of FIG. 4, however, showing a third embodiment of a screwstrip in accordance with the present invention;
FIG. 9 is a pictorial view of a screwstrip as shown in FIG. 8; and
FIGS. 10 to 14 are side views of screwstrips showing different configurations of guide and/or terminal sections.
FIGS. 15 to 21 show partial, front end, rear end, first side, top, bottom and second side views of a fourth embodiment of the invention similar to the first embodiment.